Wall element

ABSTRACT

A wall element ( 20 ), particular for manufacturing the outer walls of buildings, which is made from a composite of a base sheet ( 21 ), which is made from comminuted plant material and mineral substances, and an insulation sheet of a thermal insulation material ( 22 ) that is open for diffusion.

It is known to manufacture molded blocks of wood concrete, that is, a material that contains wood chips and cement, and to make masonry building walls with it. Since as a rule this material is not suited for bearing static loads, recesses are made in the molded blocks that are either filled with concrete or serve to receive elements in a supporting structure, for instance made of wood or steel. It is also possible to make larger slabs from this material that form wall elements from which entire building walls can be put together. The material has the advantage that it is open to diffusion and ecologically unobjectionable. However, wood concrete has a thermal conductivity that is approximately comparable to that of solid wood. This means that the wall elements must have a thickness of approximately 36 to 40 cm so that the wall will have a thermal insulation value that meets the passive home standard. Building walls that are put together from such thick wall elements, however, can hardly be transported, because of their weight.

It is therefore the object of the present invention to propose a wall element which is open to diffusion and that attains a thermal insulation value that meets the passive home standard even at relatively slight thicknesses.

This object is attained by a wall element, particularly for manufacturing the outer walls of buildings, which is made from a composite of a base sheet, which is made from comminuted plant material and mineral substances, and an insulation sheet of a thermal insulation material open to diffusion. Insulation sheets have an extremely low thermal conductivity. By combining this material with the base sheet, which may for instance be of wood concrete, it is possible to reduce the total thickness of the wall element markedly, compared to a wall element that comprises solely the material of the base sheet. Moreover, an insulation sheet has a lesser weight than a wood concrete slab of the same thickness. The material of the base sheet can, besides wood, also be any other plant material suitable for the purpose, such as hemp, bamboo, sisal, or the like. As a binder, besides cement, magnesite can be used. The insulation sheet is preferably made from wood fibers but can also comprise other plant fibers.

In the choice of material for the base sheet, care should preferably be taken to assure that it has a lesser or at most the same thermal conductivity as solid wood, since otherwise, given the desired relatively slight thicknesses of the wall elements, the requisite thermal insulation value is not attained.

A further possibility for improving the thermal insulation value of the wall element is to incorporate air chambers at least into the base sheet. The volume and location of the air chambers must be selected such that convection flows of the air in the chambers cannot occur. The air chambers can therefore be oriented preferably horizontally or essentially horizontally. With this location, the volume of the air chambers can be made relatively large, since convection flows of the air can develop only in the vertical direction.

For joining the base sheet to the insulation sheet, various possibilities can be considered. For instance, they can be glued together. A form-locking bond between the base sheet and the insulation sheet is also possible, however. It can be achieved for instance by toothing the surfaces of the sheets. In an alternative embodiment, the base sheet and the insulation sheet can be joined together by anchoring elements.

Depending on the stability required and the desired thermal insulation, the ratio between the thicknesses of the base sheet and the insulation sheet can be varied. In a preferred embodiment, the insulation sheet may be approximately 10 cm thick and the base sheet is approximately 10 to 20 cm thick.

The wall elements of the invention can be furnished as semifinished products to carpentry shops or to the prefabricated home-building industry. To achieve an even higher degree of prefabrication, recesses can be made in the base sheet for receiving elements of a supporting structure, in particular wooden posts. These recesses may be made in the surface of the base sheet, so that the elements of the supporting structure are surrounded on three sides by the material of the base sheet. However, it is also possible to indent the recesses so deeply that they extend from the surface of the base sheet as far as the insulation sheet. The elements of the supporting structure can then be joined directly to the insulation sheet.

The recesses can preferably be made by milling. Besides the recesses for elements of a supporting structure, installation ducts can also be made in the base sheet and/or in the insulation sheet.

From the wall elements of the invention, finished outer walls of a building can be made by putting the wall elements together. The insulation sheets of the wall elements form the outsides of the outer walls, since they have a lesser thermal conductivity, and they may already be provided with a plaster system or with shuttering for holding plates for covering the facade. The elements of the supporting structure are placed in the recesses and secured. Next, the back side of the base sheet can be provided with a plaster system as well. The thus prefabricated walls of the building are then transported to the construction site, where they are joined to the prepared foundation and to one another.

For manufacturing these wall elements, the invention proposes a first method, in which the material of the base sheet is poured in the liquid state onto the back side of the insulation sheets and compacted. In the second method of the invention, the material of the base sheet is poured into a mold and compacted; next, the insulation sheet, moistened on the contact side with the base sheet, is placed onto the material of the base sheet and optionally pressed down. Air chambers may be made in the material of the base sheet, by means of positive-displacement bodies that are located or can be located in the mold and/or by means of mixing in clumps of ice beneath the material of the base sheet. Mixing in blocks of ice can also be employed in the first method. The ice melts from the heat produced in the setting process, and the resultant water is absorbed in the setting process. If frozen positive-displacement bodies are used for making the air chambers, the wall element can easily be unmolded after the conclusion of the setting process.

The material bond between the base sheet and the insulation sheet may be so good that no further fastening provisions whatever need be made between the two sheets. To improve the mutual bonding of the two sheets, the insulation sheet may be provided with a textured surface to produce a form lock with the base sheet.

However, before the material of the base sheet is applied or before the insulation sheet is placed on the material of the base sheet, it is also possible to incorporate many anchoring elements protruding past the back side of the insulation sheet into the insulation sheet. These anchoring elements are surrounded by the material of the base sheet and thus form a secure mutual anchoring of the two sheets once the base sheet has set.

For attaining a further degree of prefabrication of the wall elements, after the complete setting of the material of the base sheet, recesses may be made, in particular milled, into the back side of the base sheet for receiving elements of a supporting structure and/or in the form of installation ducts.

The enclosed drawing illustrates three exemplary embodiments of wall elements according to the invention.

Individually, the drawings show:

FIG. 1, a fragmentary cross section through a first wall element;

FIG. 2, a fragmentary cross section through a second wall element;

FIG. 3, a fragmentary cross section through a third wall element.

The wall element 10 of FIG. 1 has a composite of a base sheet 11 and an insulation sheet 12. Both sheets 11 and 12 are made from plant materials. In the base sheet 11, cement can be used as a binder, for instance. The manufacture of the wall element 10 is done such that the material for the base sheet 11 is poured onto the back side 12.1. To create good mutual anchoring of the two sheets 11 and 12, before the material of the base sheet is poured on, fastening anchors 13 are inserted into the back side 12.1 of the insulation sheet 12. By means of these fastening anchors 13, which are surrounded on all sides by the material of the base sheet 11, an optimal bond is created between the two sheets 11 and 12. On the inside 11.1 of the base sheet 11, recesses 14 of approximately square cross section have been milled. Into these recesses, elements of a supporting structure, such as wooden posts, may be inserted.

The wall element 20 shown in FIG. 2 is also manufactured from a component of an insulation sheet 22 and a base sheet 21, which are made from the same or a similar material as the sheets 11 and 12. The manufacture of the wall element 20 is likewise done by pouring the material for the base sheet 21 onto the back side 22.1 of the insulation sheet 22. For the base sheet 21, the form lock between the base sheet 21 and the insulation sheet 22 is produced by providing the back side 22.1 of the insulation sheet 22 with a profile that is penetrated by the material of the base sheet 21, creating an inseparable bond between the two sheets 21 and 22.

In the base sheet 21 as well, recesses 24 have been made, which in this case have a cross section in the form of a double T and extend in terms of depth as far as the insulation sheet 22. Supporting structure elements inserted into the recesses 24 can thus be secured directly to the insulation sheet 22. Moreover, they are joined to the base sheet 21 by form locking, because of the cross-sectional shape of the recesses 24. In addition, it is understood that fastenings to the base sheet 21 may be provided. An installation duct 25 has also be milled into the base sheet 21. Pipes and/or lines may be laid in this installation duct.

The wall element 30 shown in FIG. 3, like the wall element 10, comprises a base sheet 31 and an insulation sheet 32 and is provided with recesses 34 for receiving wooden posts, not shown here. However, the manufacture of the wall element 30 is different from that for the wall element 10. Here, first the material for the base sheet 31 is introduced into a mold. There are rods in the mold that act as positive-displacement bodies and thus lead to the creation of air chambers 35 in the base sheet 31. The material of the base sheet 31 placed in the mold is compacted. Next, a grid is also pressed onto the top side and results in the formation of air chambers 36 directly on the top of the base sheet 31. After that, the insulation sheet 32, whose contact side toward the base sheet 31 has been moistened, is placed on the material of the base sheet 31 and optionally pressed against it. Once the positive-displacement bodies have been poured out, air can be blown through the air chambers 35, 36, which reinforces the setting process. For easier unmolding of the wall element, the positive-displacement bodies can first be frozen as well. The ice melts in the setting process. The resultant water, like the water contained in the material for the base sheet 31, is needed for the setting process. Instead of positive-displacement bodies, the material of the base sheet 31 may also be mixed with clumps of ice, which melt in the setting process and leave small-volume air chambers behind. The air chambers 35 and 36 shown in the example here are of relatively large volume, but they extend in the horizontal direction, so that no convection flow of the air can occur in them. They can therefore extend over the full width of the wall element 30. Besides reinforcing the setting process, the air chambers have the advantage, because of the delivery of air in the manufacture of the wall elements 30, that they increase the thermal insulation value of the entire wall element. They also assure a weight reduction and hence better transportability of the wall element 30. Between the base sheet 31 and the insulation sheet 32 of the wall element 30 as well, a form-locking bond as in the wall element 20 or bonding via anchoring elements as in the wall element 10 can be established, if that should be necessary for secure bonding between the insulation sheet 32 and the base sheet 31.

It is understood that elements 10, 20 and 30 can also be made without the recesses 14, 24 and 34 and without installation ducts 25 and can be furnished as a semifinished product to carpentry shops or prefabricated home-building businesses. These facilities then put a plurality of these wall elements together, making complete building walls, and also make the required recesses in the base sheets. Next, the elements of the supporting structure are inserted into the recesses and secured. After that, the back sides 11.1 and 21.1 of the base sheets 11, 21, 31 can be provided with cover plates, such as plaster plates. The outsides of the insulation sheets may be provided with a foundation plaster. The thus-completed building walls are then transported to the construction site, where they are set up and joined together.

With the wall elements of the invention, buildings can be made that combine the advantages of solidly built buildings with those of prefabricated homes. The wall construction itself is solid. On the other hand, the entire building can be prefabricated industrially as is done for prefabricated homes. Thus similarly fast setup times for the buildings can be assured. Moreover, the wall elements of the invention have the advantage that with them, buildings open to diffusion with high thermal insulation can be manufactured. The wall elements can be made entirely of renewable resources and can thus be 100% recycled. 

1. A wall element, particularly for manufacturing the outer walls of buildings, which is made from a composite of a base sheet (11, 21), which is made from comminuted plant material and mineral substances, and an insulation sheet of a thermal insulation material (12, 22) that is open to diffusion.
 2. The wall element of claim 1, characterized in that the base sheet (11, 21) contains cement as a binder.
 3. The wall element of claim 1, characterized in that the insulation sheet (12, 22) is made from would fibers or other plant fibers.
 4. The wall element of claim 1, characterized in that the material of the base sheet (11, 21) has a lesser or at most the same thermal conductivity as solid wood.
 5. The wall element of claim 1, characterized in that the base sheet (11, 21, 31) has air chambers.
 6. The wall element of claim 5, characterized in that the air chambers extend at least essentially horizontally.
 7. The wall element of claim 1, characterized in that the base sheet (11, 21) and the insulation sheet (12, 22) are joined together in form-locking fashion.
 8. The wall element of claim 7, characterized in that the form lock is formed by a toothing of the surfaces (12.1, 22.1) of the sheets (11, 12; 21, 22).
 9. The wall element of claim 1, characterized in that the base sheet (11, 21) and the insulation sheet (12, 22) are joined together by anchoring elements (13).
 10. The wall element of claim 1, characterized in that the insulation sheet is approximately 10 cm thick and the base sheet is 10 to 20 cm thick.
 11. The wall element of claim 1, characterized in that recesses (14, 24) are made in the base sheet (11, 21) for receiving elements of a supporting structure, in particular wooden posts.
 12. The wall element of claim 11, characterized in that the recesses (24) extend in depth from the surface (21.1) of the base sheet (21) to the insulation sheet (22).
 13. The wall element of claim 1, characterized in that the recesses (14, 24) are produced by milling.
 14. The wall element of claim 1, characterized in that installation ducts (25) are made in the base sheet (11, 21) and/or in the insulation sheet (12, 22).
 15. The wall element of claim 1, characterized in that a plurality of wall elements (10, 20) can be put together to make finished outer walls of a building.
 16. The wall element of claim 15, characterized in that the insulation sheets (12, 22) of the wall elements (10, 20) form the outsides of the outer walls and are provided with a plaster system.
 17. A method for manufacturing a wall element of claim 1, characterized in that the material of the base sheet (11, 21) is poured in the liquid state onto the back side (12.1, 22.1) of the insulation sheets (12, 22) and compacted.
 18. A method for manufacturing a wall element of claim 1, characterized in that the material of the base sheet (11, 21, 31) is poured into a mold and compacted, and next, the insulation sheet (12, 22, 32), moistened on the contact side with the base sheet (11, 21, 31), is placed onto the material of the base sheet (11, 21, 31).
 19. The method of claim 18, characterized in that air chambers are made in the material of the base sheet (11, 21, 31), by means of positive-displacement bodies that are located or can be located in the mold and/or by means of mixing in clumps of ice beneath thee material of the base sheet (11, 21, 31).
 20. The method of claim 19, characterized in that the positive-displacement bodies are frozen before the material of the base sheet (11, 21, 31) is introduced into the mold.
 21. The method of claim 17, characterized in that the insulation sheet (12, 22) is provided with a textured insulation sheet (12, 22) is provided with a textured surface (22.1) for producing a form lock with the base sheet (11, 21).
 22. The method of claim 17, characterized in that before the material of the base sheet (11, 21) is applied or before the insulation sheet is placed on the material of the base sheet (11, 21, 31), many anchoring elements protruding past the back side (12.1, 22.1) of the insulation sheet (12, 22) are introduced into the insulation sheet (12, 22).
 23. The method of claim 1, characterized in that after the complete setting of the material of the base sheet (11, 21), recesses (14, 24) are made, in particular milled, into the back side (11.1, 21.1) of the base sheet for receiving elements of a supporting structure and/or in the form of installation ducts (25). 